A federal judge has ordered the federal government to stop threatening local and state election officials with criminal charges over their role in processing election ballots.

The California judge ruled that the Department of Justice (DoJ) must stop demanding that local and state election officials set aside or not process certain ballots that the Trump administration alleges may come from non-citizens.

The ruling comes days before the midterm elections, which will determine which political party controls the US Congress for the last two years of Donald Trump's presidency.

Trump criticised the ruling on Saturday, writing,"Why would they reject fixing Election Fraud?"

In California earlier this month, the justice department sent letters to the secretary of state and Los Angeles County Registrar demanding they set aside the ballots of 20,000 registered voters whom the Trump administration "believe" are "likely" non-citizens, according to court documents.

About a week later, armed officials from the Department of Homeland Security delivered letters to county officials and employees across California threatening criminal charges if they didn't sequester those ballots.

But the groups said they could not comply with those demands because they must follow election procedures required by state and federal law. A judge weighed in and tossed the demand, writing it would "wreak havoc" in the election.

Around the same time, the justice department reportedly began a criminal investigation into county election officials, issuing federal grand jury subpoenas.

Civil rights groups and unions representing election workers filed a legal complaint, accusing the justice department of interfering in their duty to administer the election. Judge Trina Thompson ordered the administration to halt their actions.

"Although Defendants claim that their actions are designed to halt unlawful voting by noncitizens, their actions are likely to have the effect of interfering with election administration and disenfranchising lawful voters," Judge Thompson wrote.

The Trump administration sent a similar letter about alleged non-citizen voters to Washington state and demanded that the secretary of state there cease processing the ballots, according to Thompson's order.

The manoeuvres are part of a yearslong campaign by Trump and his administration to fight alleged voter fraud that they believe is widespread, despite research showing that it is extremely rare.

Ahead of the midterm elections on 3 November, the president has cast doubt on the security of the vote - alleging "rampant" cheating in postal voting and non-citizens voting. The president also offered a $1m (£750,000) reward to people who report cases of voter fraud in the US which lead to a conviction.

Studies, however, suggest actual cases are extremely rare. BBC Verify reported that the Heritage Foundation's database identified 24 cases of non-citizens being convicted for voting between 2005 and 2025.

In his post on Saturday, Trump said criticised recent rulings against his administration pertaining to allegations of possible election fraud and vowed to continue fighting for "Election Integrity".